Two and a half hours in front of a parliamentary committee is probably not something most politicians would relish.
But for George Osborne, this was clearly something he was looking forward to.
A chance to put his bungled budget behind him, and prepare for the UK's next political earthquake.
SOUNDBITE (English) UK FINANCE MINISTER, GEORGE OSBORNE, SAYING:
"I'm very clear, I think our exit from the European Union would cause an economic shock, or a convulsive shock as has been described recently."
But that's not what everyone thinks.
Same room, same questions, but very different answers from the other side of the divide.
(SOUNDBITE) (English) LONDON MAYOR BORIS JOHNSON SAYING:
"I think the best analogy I can come up with this whole debate, is the Millenium Bug. People said that planes would fall from the sky and that computers would crash and the economy would tank by five percent or something. Nothing of the kind took place, I think there is a great deal of scaremongering and alarmism."
That argument is certainly finding favour.
An ICM poll this week put the 'out' campaign in front for the first time.
But crunch the numbers, say analysts, and leaving becomes less attractive.
(SOUNDBITE) (English) HANTEC MARKETS, MARKET ANALYST, RICHARD PERRY, SAYING:
"No country has ever really had a trade agreement agreed within two years of the EU so that would be a big problem for the uncertainty of the situation."
That's something the government will seek to highlight when it publishes its own assessment next month.
But in a sea of surveys from both sides of the debate, it's unlikely the waters will clear before the public goes to the polls.

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